SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5da41fa20ee1a9f75251bdf88a9ee9071bb4cb623a60d8c435ced79c0057d049' 
  AND token = 'X7iGBkUPICoohdFnSxwDxxY+ZpeRwm5ln2m5Uf1s0HM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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