SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07b66cdb8d5c7ce5f17965c55e19ea35ec4758eaa83941034caddf5dcd61acab' 
  AND token = '1ZMjmRaQ+jfGS4+YqCTAFJpMTgYzx/yl4gFBTbA6kK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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