SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac77a240155dfd61feacd0dbfeb839798406bded020d2d16cb2b5f9280286e65' 
  AND token = 'Bp9qo5sKxH7DyuuxBLlsLGeObQJO37m3IXzH8V2Bqqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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