SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cb50befc00f7ea48057d66850d16d7c74f47458103a00371c61ff08eb1d541e' 
  AND token = 'Fx0TbKqFR+EDfTJB+Pg+70ZmkKED5+MUA0cMQP4SvYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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