SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89da81dd485d1108a2da21f6ec85e5bb581125e94ccbec4d2fb787b822b90be8' 
  AND token = 'qJbsyib/YxKIggJb1hODpRIZI9N11R4QPufjvHdlhm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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