SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '08d836dd14e45f388696b85c27d11ea0e30c9977e7bb07a4762599557d14292d' 
  AND token = 'XvSIWFVVfyAlqzcab92GqnsAw7zQmuUhOw5PZOFaOJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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