SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d6f2f9cf766c316c1a3d1a720db25f3fde5ee379ff070454ffd79b634ad7343' 
  AND token = 'YA3rsaby5tGmdVVAoQhiDmYOBxogTYyQX6a4dtLPuqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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