SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c0d7a6eb39f56a521dc3fd1ae437149d5bd3913a6c77434950aaaa37e93e67d' 
  AND token = 'xutENKfjDS191NW7bRoHTXHzxS6oYhCcveOd9KuenMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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