SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af2a9c1aaed93170eda91e2bb40ad117d2b4799294bd8ca0fd20cf31ea617922' 
  AND token = 'cCpsVxeRbxgWZQ86vANtkK6f7/2JdiEJqdgf5PxXAdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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