SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a75f290be64dc375dadb745f4f315e5e84761f8dc87b7bb18332ba1c8a19f9a' 
  AND token = 'j4GF1KyJ1WEwHVYGX16pEyPBd5/XLm0Z2OB8Rh7FAHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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