SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a2fc7f8db068026db3dc8739cf3b8b5c572dbe1a31e60996ccc6bf4cf831532' 
  AND token = 'PjDiGJ907vayOiKmoBfB8bKhI7R2UioYqOpQlqwtrk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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