SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9350f40a3214f1c09dce51b8fc9aa57680a46a226839c4469b4e00888310724a' 
  AND token = 'OPat934muKKh+QpUiiUt/kKidCQnya6lt6AxsoCYoQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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