SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e62416a2f87a5bf309d36b70b978aa80f43566abc3d9b2b854b9c1cbb7b86458' 
  AND token = 'M5LknAzRd3xvJPYW+818rps+FQaKwTiDO1dIPw2j0mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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