SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '680a337e7f8246cf9dc6c9e9721c5dff70d272759f05659dbd3b92371618bc35' 
  AND token = 'omt3YkjARpHAJLuYqx35n6t2TcuuAI54FjG2VNvSYJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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