SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8604032b539ec51f4e5579743489654fbf25fb08a12a80ef580ebac807a40e1' 
  AND token = 'N/+rQKSv3TBmWSI9kOpyFoBpZCR+jyFJOGu5DKdxuiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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