SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8b1cc088da73f2f4d227ea08bf9fa56ec222fd5f37429fcd3fdf20abff5bdf4' 
  AND token = '3t2e85Cb9YPFZFRM0vg+/GHQZ42eDgasI0y0ZlUvPmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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