SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca8059d131595a6eefa94f90a1ed6d5151e034fb3ac0b5f537989d37b41afe10' 
  AND token = 'nnF+nG6T9zYXSZi/NmJT9eCU0MT5RdEcsG8EJx+5YGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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