SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92c423d277ce9f00d570224f2c95bd4c1d2647d15393e574282f7e00bb58d1d9' 
  AND token = 'WMIiPeTzWI1gwcACN+KdDXSgSmrMDZjGi/rwOoZ9bfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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