SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f9617dff19d77372caa676f4e19e5b5fddbd5ca31c7dd55923b5a7a75a310a6' 
  AND token = 'QmZvyxeDKmNj2Fr8cgHOXUgTjX3hE/w4uwc4JCU+NCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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