SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '932b5820f325ead7750d806eaf776f3efdabab763f1394ff72f83fcfbcf13bf4' 
  AND token = 'fB9QQIbqJ4SpVG9eNw/0nvJFLlzHqk+pakPuc3TZOUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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