SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8feaaeb0ff1c46a662edde36a3b9427aa9993d3a378fbf8fd58cf674a27c9c6c' 
  AND token = '7Lb07uaHswsPRfp+CPmaxtvqFgAJGbu+KioyfYeqkZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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