SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3acff695f764429aa68d00db745ad6d765024c9a608083565ae873a685ca20e9' 
  AND token = 'xsJy50kapQvy8nX/srOMKEG3K8vZadDZmCk1EfUlxTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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