SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3785ad0f5eab32790ffc6cd61875a0194b74ea3606a323e6c4ddae5bca187da0' 
  AND token = '6vPLKfRnixcyHDSznsboEHVBHkTnSEXdQ/07Syn7h/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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