SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ea247ff75861cedf4fc2e7e17a6786af8a6533cc9c05b597d7f52e70c924319' 
  AND token = 'p7tocf7J6lePEfWBEGZLzeLk5jEA9FuN3OXmXGa2oAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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