SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '56d5be6c4b8e851d301eaa0aea40122c36cce3e09ab53b285950b770038d9a46' 
  AND token = 'uK8dwCsN4n0l3I3jyvzt5QpuWXROOxG1kycnefs93W4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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