SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64c071e39887f586de10953539544d76b4319f74a4b278eaadab33d616b5399a' 
  AND token = 'itdyyVptcSNLIfOwCbJhRx8cjVpoBL1WYJclz+Km6qc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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