SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57440a28a16ea89c1e42137cdc795af52edcea83eb88e0f3df4319ab8ad30dc3' 
  AND token = 'AVqF50VpK6owL+5hJqYCMnPsbQJrWjVAkmE5B9jbx8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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