SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a36274e53bfcb9324d0ebe0c124edde82b12ef3fd9b88a7b26520800f5c539e4' 
  AND token = 'Zx6QSDewPGTpU+YlVmkv4c9I8eLBZuxng/t5J43Bp1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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