SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a58417a9cf58d48108ea527401bc0eaafd214ad4686017ed78d816d6a0b589fa' 
  AND token = 'PeAx7DU/WNnjEyNbZXLjJlR9iFa7an2ItQVOL1Df1MY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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