SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5892a40152aa7ccb471d7570be16a93d75ff194a20edb8a7d3406e41d1b036b6' 
  AND token = 'iZHUlQE3NIa1GZwHlqOmmMRpW5/BCU6br97SNcWe++A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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