SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8cc649745469d771a2dc52dc2de7348b6376c557701c844040c9040916f7327' 
  AND token = 'DY6faGxTOau9vR4/8mq+jKyU2Z8YwAh0BqBcz63uzio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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