SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7366fd993b7fafebc39376c685d6b6a5b26a2d801195c1cd17f48dd643043058' 
  AND token = '2zUCjSdRQ1bdkuOazAn077BgnkpSnQKt1IWvnCYWjPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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