SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '384ab52865bd5b47d5820c1f98f3e3435dc84956ea929414f7baec5017ab8629' 
  AND token = 'sFq/ijyYzCmpYtcxzmARME6hJg7kK5gA4DYSRfWXD14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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