SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72ffefe0e03699bb568cc81c62a1b16404afa3f708fc57486519a1fbf7854b20' 
  AND token = 'GFucuusssRkhUqssXtNDS+aedvV+aIaKNFUo/MpN3sQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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