SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9df611e58d414081c5222a16917a5efcc7eddb118b0b7136a04c8ee08d473921' 
  AND token = 'yOyiC8KfmJLMYMByyBGnNjDbDIGpYRanYJxEKaxZZYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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