SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f58321267f25c16eb4a53f805d14f5d69e77b2e5bc8f5fd13b7801763b93b742' 
  AND token = 'rwkDUlLZh+1RHjWQwGU5NQGqy7iAdVgBOOm+7zdv2q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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