SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdcdf707484f10258cb3d3f0e5530fb1be13f302cbc8b72f8ccfb1b81159f20a' 
  AND token = 'z5AITe7X9JUtM9GuIMmh7h2+vNAK/TdWs0X9H0qTQQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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