SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58df87954f2087f54c34618ed16da6f137bdd8b4f4654dea81c3817872576052' 
  AND token = 'it4evhthj4pNMB4aXTCfXvUwybNQwmjNamPcnCZZQgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}