SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89f73e9e6d85371b0ba068b86ceadf1744addc7983c258fa31d26b492f41fe82' 
  AND token = 'blKcZkbXQrvUcgiOBH1OXsn9dtKNTPzxLr+EBWkf+jc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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