SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69bc769b11c2613f5f806d544b5a8eb586e63027b81a0168f284d71de1c6fc50' 
  AND token = 'lwjWmMzH8jwNzmb/v0zy0cJln1PGZvs05FbKOLRvpRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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