SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '190dafaa91a169c88fd5980083e3602cc9aa259d180353b2c229090cd3b35caa' 
  AND token = 'srmG6knz3ZG4OtubjUjosgf2Z/ZadvHgL/wu4379eOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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