SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e34e25dc5f9a4815d47a21ca44fc67d7ca79ea28ce577ebcbb544d130ec92799' 
  AND token = 'YlOLEzhNnHOwxw+S36NAJdNcPwN31iHNGyiKtInP08c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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