SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce7775dd257e0999dd506a1362f1cac432623400289b982857a98addd621e368' 
  AND token = 'es+DCjiKjoP8bGwP4uYQM41bW3YvA9Fk0dMIX9Bvblo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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