SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77ba89ed287039de5b54a40f0fbf6d92bf8570f40ccf5222bae9be00c837d574' 
  AND token = 'qO9FQYrClJi9JYqXpd7f9Axu1gGu3aaqyjv6SPhuhaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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