SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '541aa14a876c7746afd09f8acfbbaac093083f3def6529d5a668b65b80e1293b' 
  AND token = 'zGwQIkB85mWNRTXikSFgWQiRYCLL0KLZ3/N+ujgh3og=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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