SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8482a230fbbed84cf9ca0b8ea5bc00b278ccaaff426d8c432bc3707aa0c85e00' 
  AND token = 'WbBGvdiwwJZaMYeCWEiFK71SFTbTXZTSP2dVsRrAKo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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