SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b12043b5254164030a522e8786b6cee3eec48a30f11cc9fd79036254d89d05e6' 
  AND token = 'TgJG/PNldI/D+JlSC4h35MYJI1TMKOvBz5fdDMbJlVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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