SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a11eeb2ab7608dee2c2f1d6c28691b1ace942b1c31ce246e650362434e6f864' 
  AND token = 'haH/xLTEoFga0kYAqanUappsRJj7nHXvRwfJ387LAfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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