SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06c51c307bec45d6226816ad839b17d098f6a82397142adb2ef9ac1eb8776caa' 
  AND token = 'AlIeLWnJYns2V5PvnKK/mwi/DwhkQg71A6/oRngubAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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