SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbd2199748745e1f2a6d4d35eb3de6a65c9ecdea19feb9663fe72f44c51a7096' 
  AND token = 'Mxt8yu1RPz2Quw/m/Vo3s+raqVLg0KlWJnkpTdhNuRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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