SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bc7ad11960f5299e1f740f25abadbc071ae4ac6d27a1b3653a6692b8853e237' 
  AND token = 'JMzgHNV2MwmnL5HTYS57vD4KRx+Q/bdGVcjDa7WL+NU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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