SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea1fc1ef09cb2d729f9cc6ceaca914fe248d329ce6a3d25b98419df2b1468a6a' 
  AND token = 'oeFDQ9MnwoPelohN7j7QAghIS1ZvJHyNWqAoBEiqwCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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