SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0154fd39631d0be592341eede5df504a2bc5a1daea42403e42a0edc3668cbce3' 
  AND token = 'qDwxXhyqj74Kpgfb0hJsVvruWiRgPQpm96ldJ+ircMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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