SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '680571443dd44782dce8f86d979b4994119647dab54ea0f23c9faef7490bfe06' 
  AND token = 'ITM5XMDbHj4yQ6Oj/UJOyJHnT9rD075sWDi9OlIfhoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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