SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e9e6937124e14e0160623822d4460e1645769cd7aaad9222868b9478de31990' 
  AND token = 'E26jqKN8sRRGt0yBHTtVhlAJiIpyYU+tFcKiZ1lj3jQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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