SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88eeb8fe4f89f7b99c94f20b2c18a2c2c1b756dd0d5c30cfe228631ad37662eb' 
  AND token = 'OnX4szYpn7Qppcaw8Ky4meKjZRvveiXxlCLvY4Y/4sw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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