SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1493a35278100dc2c72cbef4eedd7dce14e80c8f810a1e88233409e305785022' 
  AND token = 'vnbSkPo89kzBcgVp1ywU3aTfwknRMXwkkvrXUkBx6I8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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