SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a44552b89e1ce7db7afbf18a6f9dde836088b7fb620c6698d1d325540f2e379b' 
  AND token = 'nXKG+80Hl87ac45srCRuWAIjh4aN83xq/Z5OvKCVfIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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