Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac8eb2c70137029caa15d4abc5f5949d420f442a9fd0405b584cb30c59b66d20' 
  AND token = 'uzYuBsMOcUw8Fzo7jbsMwipwYRPyLjMMr6Ux3YAr8QQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}