SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '386daa2dd2842ece15ed5c421958397702acdd00c401c8d5c59da721aad0aaa0' 
  AND token = 'yZrN9yLGeu7g4UaQyOotBPMBOdCJlqnoq7ggVcCE8Us=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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