SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dbd00fab785bdf4acbc1d33eb2f663024a6bab9be571b5c7278d36cd09dccad' 
  AND token = 'sVoFajC9BkuYGlQi7mCm1sR+Dttf8Em6AfGw8xeOvtE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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