SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e2311461080097403753fe95894d2a42ee26d2b52793c77fc1482151669128e' 
  AND token = '97Vf+5rKLr53qVYh/uCYE6qncZP+s/iDB+EYU14fkqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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