SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04a364acefac95665759b6cec301776fea89d7f45c6629a96492949432f7441b' 
  AND token = 'qi6eVcoZrlVEuQj7POGOnZsXPuvuxyutMRqHtmJjBl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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