SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7760b91830f0a415c88a1ebd95ffba499dea37bd2825a2234951a2b68d0bd06d' 
  AND token = 'MqtD7FRQpZqLCCWO/2qybuwA1dti37+USEGrwcwq3FI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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