SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1799178f5374b5fba2909bf744f6b5c1ec04eb164e503d8c74b74e5653718a4' 
  AND token = 'WBE/xiIu+IhW+y0jORvl2v1HuvKwE+3WJb4SLdTuUgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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