SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7228955e699f5f37c383f810fbff0834ea2622dae0d8ecc3987729c6b0fbac87' 
  AND token = '9qOx8PYdbDj7lPlIKyW6a+3vgHhhPGI1gSYuXLIqoCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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