SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70fa097b2b78337a3286338ce9af0d9534c7b295f44e7969d105f93d1a71c8d4' 
  AND token = 'Pg8JE8INMoyhSGumDgv3nR/BuSik7rXvjyxbggvnZpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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