SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83a7d75eb646030eb92cf48c86771a5f92e5fcda0ce24ae6bf0af50fa807adb6' 
  AND token = 'WaWGdpov6Lof4tsil4ZFL8h2BAXetEWNT0OtXIO7FXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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