SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '964fc73fc5c46aefc7b729cedf5f82469cddb403ab1ba407ffec82f7598b0d9f' 
  AND token = 'vwM+gqBfsVxHDhdOrj5ql9j/FhTpA/VSQzmHU85GoGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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