SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4d6f7a65887d5632417c28bdb82805679c7c89a669cd902a0745d800dd09ec5' 
  AND token = 'xVDOQtR6Fz0/flSyb2o07BrPZ2ZJzyxp9wQ4ZbzGupA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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