SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8016d10b09cd5e8d3011d0f9defa9ff7a4a2b8222825025e1f9b0292fe90a6a7' 
  AND token = 'UmNL4cFYwNFaALqFh7jtwJG5mHMlFEIp+AgInXVK8ug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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