SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c99548e8fa3f228b6be4c70f06577a83e6fe2bdb91afa780c3a50ffdbca162e' 
  AND token = 'eVJVzMnc9Nu75zk4ceAHG+zEQXBYVdqH0Y9FDQYt32k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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