SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '264c124ad127069fca635504dd953042cde49e459c88594b11672fb30192f1e8' 
  AND token = 'IERYeDEAhnSG9m/LFO3fN3/4VUC/BWhsAqwsI4hjh9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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