SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c19984bcdc53664c2c59a8479ef0aa1a9577d710d4baa582557616a03c61f94' 
  AND token = 'Fm+H6zqFElHNjsv62HpFdlx9fWrSeoq6tkw86gDpcJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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