SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32323afb1154e0a9479b1659dfe4c489952f05a6c2965b584c3a003e899d834e' 
  AND token = 'w+gtmDX/vT1M7yBxx+Na/SPVFCKaNelOf6+ahHDUH6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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