SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36ccf091fce31c074f67bf0e44f74cba2a730aa0b6444b772804570fd7075b27' 
  AND token = 'iHQB/7O9zT5+83lCBrRYdZjhkqYENt8OOyp91fr5aGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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