SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7849f7b6b6e1541d82186d953a72bc28c0ef23547c59053b8b316f2623a2393' 
  AND token = 'cAiskzqWu6vmJ0jwwkpZuZHA8VodQQ/Wf9zdDZLtcxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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