SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e59f95aa82d579bc66cdf466175e342e48e942ceeb478b925654e743c904eb08' 
  AND token = '5N/P50SCQJHP2pH2Jax22QJXfV+VnxDI4Ksy2bMltR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}