SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '930ac988a1993bc930c3b67fcd4106fbda6831b6554f7e7b35dbac86afdce1c0' 
  AND token = 'o4fbBcuGPqExKdaWb8i/DOpF8vLOkLTDblmBbMS8mkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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