SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2a211d00a8ef054e8644e800c9da8d9ada6f37ba111eb7f163bef94e486f7cc' 
  AND token = 'f066UkO6EA7R2T2FlXeQOAvvkyUtyZtxmcDw9pjO96E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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