SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66c52d8bcc052f134ff246f5ac862949f7131931aa25211efd314a2ce4509116' 
  AND token = 'Gi8z5dxBBiOA4LMnFKsHaasH8UJCWcP+hrx0OvbuQBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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