SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd27ff8cfc408511b0fffc4fc131b29366e885de79b03eeebb5d6425e6ad0dde0' 
  AND token = 'yBxmNR/v0ao4Tu0Ki0w48lDW8/o3hLSPUG3Vf0RGUHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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