SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79c03cf97498b523dd27a1aa6e91ec546cb6e7cd702a5a2e23fc45544195a72f' 
  AND token = 'Bil/EAgK+dZH3t7z6KvPRvj5afqjKrMTwWBtSxjISs0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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