SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '683cc9d80e179d11bd0a6c10f321b17726179d510284624c60b234a81697b99c' 
  AND token = 'bhQIA0FSwmaIQ6EES2mxZkjLbV1RJaLJ/RS9yuxB/b0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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