SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '550b958af5abc9b325175817e3f5c945518dcbfac84b419dfa3ee311f8ef6e39' 
  AND token = 'hXh52VYyvrK6Ffd0vCPvgr0hU72PlreNHyuTGA2tC1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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