SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe2eafb24a110a7b6c5d78241c3192a9bfa2513ea7edb51f32a788587aaea2f4' 
  AND token = 'DyKzSq53VbfjS/ERV7hwKRd3mBHAy5C53N7IZFnCUzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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