SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '905710e3943cfe519ff7179cc3d9b50b41ab5a733e06e2c2d7ae09af9d18d0b2' 
  AND token = 'kPdcbVnlms+7tqTAhVn94i25QBf1KFYrh0dWqW83LMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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