SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1af61facd56f96b4b482a9e9a41e921de2a9392edb4a688d070ee648650484ec' 
  AND token = 'KZ2FzIVRZQrf4iU9+LWE1YjoPGvqBBh2TBlKGVnwVfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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