SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f74e0e7d3f089402c14aba0357198ade6e068677bcc49f105dd6758839caf82a' 
  AND token = 'LeE5EKxsTQlssiOQnxA5nQoTqdEWlaxd45vc2NBFbP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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