SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c8fed3576795aa93fec523eaa37e8701ebb5f1ba94602efb2871396a394f4cb' 
  AND token = 'hX8mIMGbX17QN8k9wjImQC1XjIcweoeObJn7ajtGKpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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