SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d4b3bf1c2639d3106dd3e367e994f5e2bcca5c6cc2380d7cd0c306289e66287' 
  AND token = '/431/L8fzqPkqZq3jdfycj9J50U/xK+M9qSa8Qq+CTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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