SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8c008a70e2cebe5353ecf52ce2ca22da2eb6c49abb716c001a592a29ec3e9ed' 
  AND token = 'Z86pHoQMtesuY7hbPrc6fewUTVrYGAHUtAuktRtV4SA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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