SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a40d5cc73caf4bd0b0761d9ff670face14165bae59fa57978bd0e5eafee1c24a' 
  AND token = 'suhi0dHn69gYigGP5qCCVomlvOU7P/v/5Z2TDKh93Jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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