SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f913fa7e8df975d66a211b66b59163c132fce52c8e9797f7c2432eddb34565c' 
  AND token = 'tuSiuBDYdXtAbbLJElcRRQIUw49dkQ49RFipoJc4nWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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