SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd3c2f3696973101a28f96636e120bd158460b9fe3aad33f270bb88961d113b8' 
  AND token = 'fVqtF9EDqainAf95no+eqZL1nDTfH5jstHTiIvqpw4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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