SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbf8f0fc6e1a763f4f330a6fb46c9e56d5cf82a5454f3616bea430f3a711a64f' 
  AND token = 'RpjY5gjJgngEBZoCxDE0+qI7FxKPWYdBZAwEYDhrjoU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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