SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '584a377a2520e1d6e5fdb588137b52f2b25dc2e4bec61eba3391b6336b4736e8' 
  AND token = 'lE9PtmQcF0sBhf3TmELzeBwZ4SdhSuEEZv81Vb8PkcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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