SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45972f063a28f833de07f1f1bfba88935b5807f1a446bda98c82b88452d07dc5' 
  AND token = 'fMRToSOVvzLAEWz7gHGxBtL6mUWDPXDZsWZwKZdxk0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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