SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c74a5350cf590e31f8a279bfce9870696a2c814816317a7ab46c10088737b277' 
  AND token = 'QeCTNRrDnRNyE+bHsJUDwfepY7PIBbUKKA7PZg+LZ9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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