SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bc47cbe173143a3a67b41fd37901fb178188ebe1b7feac1d09c498729ca8174' 
  AND token = '31H3yh86T8zo0zqvIIh4LcocziUmJhw/zX7RGaYF4WM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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