SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2a13d5920c574ab372256fb0a78779f19031f1b748e3a64aa953b62c54bd62b' 
  AND token = 'VBuh8IQxzFAjgZtWxZ4+56tvdYpo5qCj6LXdIahN290=' 
  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"
    }
  }
}