SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35f2af5f9cb7b6f33d9289ed150d5d48fbd389cd1a7958f3fd07ea8b5cbc2927' 
  AND token = 'bTFlT4py5yW4RIuVHch8O+FCw1UGNcmn0unEjUgoFLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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