SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5adc7a940558fe657319e78ed316c9e0193ea70b7886a2142c4ed8213cdedd89' 
  AND token = 'jBInzQYZGRO6KuT8M9T9hLyP9fbKw9OpZwkF+8svNIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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