SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a442e7486257021821c43d2a4baa82f951aa6a16165aaa5267181dbb80b71d56' 
  AND token = 'IhfTd+uhkhUThvojT7GXdpqPK9N/cmF6XHmd5Dn7cqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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