SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d87eba6a9a080c63dbf114164f2aa7fa96fdd8320bcb8fe52faa6812d13113c' 
  AND token = 'nd0iOZ4CXjn0bHIeL27fXQgIC1s75jaXm/DmrSfyzqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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