SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfb4a38f53a3a4fea164f645fc8d16862b2e3d51dccd8db8ab7307d105c38193' 
  AND token = 'nAPgu+8XodNC6vOwfZHJyWVXSBUJo3UaVihdMtKr9QU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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