SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa8178ca6cb65492205943be71aa1f75fc8f1fcd203029c2a047c0c410087263' 
  AND token = '2fkdI8jQZ0spo/lzfK+7S/H8f4wXp1FNYiVqFnuQB0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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