SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ceb6d6842d8fcfe73de887c8292af89829f97449fae0d841537a20c3b6c68d99' 
  AND token = 'dqbR2pHuZVP2A+d6DUN5feiQgsJBj3FmH0/oKc3qzQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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