SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f81d46bc24e3523e74741cf08e4469f6b7561ed8b491018fdadd65e171efbea6' 
  AND token = 'GvvAZW9K4iQguqBO2ZtWEd692VSn2rzsMdJGaIMsghY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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