SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '547ec10b6b3692f0280e602afdba89705c37e94ebb134f4673264e70dfa444d0' 
  AND token = 'BCFQApwTjO7YBzq9ClckXazAvTZ0jRATRZCuhP30cbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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