SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6649889a88f317ba364dff7a36e3b36f41f552d9705f5fc64c417ea0cda8d3f8' 
  AND token = 'J7+9unkgWPyFtkl36YtAubvUCVZ/pbWDgDtaLJvZqCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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