SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cd007530da21c5900baf0633c68eb14e367d901e6e33e9d0e239e8cad35ab82' 
  AND token = 'WzVY8pzWXcpWiYX9AB2BMUM0mT0uGreaSNSTISEgI5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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