SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1517d73a95e0bd457bf1bcc3561c8dac7d96f1f06c31dd8af9e4929f1666d1f2' 
  AND token = 'wfQZvZelK1LddoVyDmGhU9wxNL7pc8WVFff1qmbQUZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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