SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '189f750966a8a896cad80d73dca55d7d8864411571d600c072a0192b6f586660' 
  AND token = 'g5hlr+M6CKOdDmMU2WQnjHm0Av9TzAX3J8Jx5YZuosU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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