SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d6dad2f685b656d483eb1d91e54b95945d173d75803a0d3ebb0a3c0e81ad4e7' 
  AND token = '60fSrEUO7MqJ/x9LTmYj24Xm2YpaLwowWpScG7pe89Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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