SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb71bb63f5f2a704989388beae0854d7cccfec6fd2fd3a3b41b34698d01a00f4' 
  AND token = 'IxFKlTWaxYPZLkesfvdqOyNzy9hkhSPpMXoFwbwaReQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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