SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe36a78ddacc3ce9b6f9dc4a8276fd3a562204ad92d84fa9bda81c36668f75ba' 
  AND token = 'E7WL186iYePhT6MxRZs0YvqaE20ODMgEGXEsQ1c/O/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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