SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4847569b694fd7826e3129237e249c668e475f2f531a9090c7f3156722e405ed' 
  AND token = 'yYAq8H850ADBjtPRzmytxGuSI5ZT58YoQ9HNZX7ybcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}