SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b0d417b232fc48230f48449ef5cbaf5c39033eb589b5c771cb1b70fcfef3a96' 
  AND token = 'Jf4I2ENvmnZeWVYpdnJJcBDrc7lulRklCEY8nIC9Abs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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