Sandbox

SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f50b32d1b8fb96a4ced0c453ccc91d6ead3999e4d42a3eb909e16e6b36072dea' 
  AND token = 'WKHCiex0SqaTFD5Ca3dvP2BD+3ffJs1v0jDQr6Mg+yI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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