SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47fd1eba35020d8608faea7dab994f37e5e43f487568cc36f1b8034c05f05ddd' 
  AND token = 'zCw7igxnhzJkv9Db+yGMnm/49L8Br5IvU7gfzzalIZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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