SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19c14bd4133a8e98155dc01a0677e731ec6af15981ebf782ddaf41751d5604f1' 
  AND token = 'OzOgDM3QnHSlz56veLGkCLhyFdyNqCEd8VoKy8i/Ng8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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