SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6c3f42d6180e99e684cf4f09a8fbf451ba23df2c4111a56f018175db86f5475' 
  AND token = 'PtBs8uzS2EfJHCyYexWLLwTkXLuBovXjROGhU+ws/QY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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