SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7b47f249da36a6d823f31225cfc19be005d356ae151209f25cf12c94a46fb53' 
  AND token = 'ui8BlA0aMPYqEC3/7VIze+18BjtMv0p7SzN/eg3ExiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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