SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94c6abebec9b9790a4da09bd43e852533bdbea519ff850cd342198bd81ce38f5' 
  AND token = '2AT1edttsHs1R8dCqZcKYdlVuCbsozfg41wvL45kg3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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