SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75d38084c5487b49cab2035f0423261abfc1ffab5bca30d01abb9c9beef16052' 
  AND token = 'V3CfJBQlNyfIau/EDcMaqDTnSuqtIwrtEJRwkhZ4pD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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