SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd770728c1f4d166cd0024b0ea56f6476b472ab9b147f95202024c6f247ad8354' 
  AND token = 'jkvsw0iJ4kz9zFaLhlgYZ5EosAyTLz+ZPQ5v4BviqWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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