SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d67eb67e9c44bc344a28bd374a5faf6d909b1f883f876aaa08f5246fac44612' 
  AND token = 'ioYnlwFXbpeCVuYXTczrcbAo0KuFs+22q9mmbpjXfR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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