SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25f3a41a178668b463068ceb8dc09e5c2f35e7db87a575814c09414816b9a170' 
  AND token = '5H8cwsfqzlEQb90RgEUhYJtmKJo9URN+XMb7ZIIGwcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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