SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5448415737eefb9adbd05cd2a487c8f1c23df23b2237768137156573d3e3d161' 
  AND token = 'FAQoTZY+gZxkjzMQJ846CrtvLGfM4wg/sisYCxz5JO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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