SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8637b081cf5075f188095ac8c655844f6c03c1dec69c8ccc8e310267381da98e' 
  AND token = '4m15UHTgBVTX5/MHNvmYi+WXEs0DYypSTLBxwtngGjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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